Organic materials, both natural and synthetic, are conventionally protected against degradation by ultraviolet (UV) radiation by incorporating a UV light stabilizer in the material. Many classes of compounds are known to be useful UV light stabilizers, with some compounds being more effective than others. Particularly effective 2-keto-diazacycloalkanes, which provide stabilized compositions that are resistant to degradation by UV light, include the 2-keto-1,4-diazacycloalkanes disclosed in U.S. Pat. No. 4,190,571; and the 2-keto-1,5-diazacycloalkanes disclosed in U.S. Pat. No. 4,207,228. Other 2-keto-diazacycloalkanes useful as UV light stabilizers are disclosed in U.S. Pat. Nos. 3,919,234; 3,920,659; and 3,928,330 which teach substituted piperazinediones.
The compounds of this invention belong to a well-recognized chemical class of ultraviolet light stabilizers. Compounds of this class include piperidinyl-triazine derivatives such as those disclosed in U.S. Pat. Nos. 4,386,177; 4,356,287; 4,321,374; 4,294,963; 4,234,728 and 4,108,829. The above patents describe oligomers of triazine rings with monoaza-ring substituents, and teach the particular use of these oligomers as light stabilizers in polyolefins. The novel compounds of the present invention contain 2-keto-diaza rings in the oligomeric backbone which are bonded to the triazine rings through an ether linkage. The novel compounds of this invention are excellent stabilizers for polyolefins and exhibit resistance to solvent extraction.
It is an object of the present invention to provide novel 2-keto-1,4-diazacycloalkane-triazine oligomers which are useful as stabilizers for a variety of organic materials. It is a further object of this invention to provide novel 2-keto-diazacycloalkane-triazine oligomers which are useful both as UV stabilizers and as antioxidants for various polymers. It is an even further object of this invention to provide novel 2-keto-diazacycloalkane-triazine stabilizers and stabilized compositions which are resistant to solvent extraction.